A rectangular channel is $4.0 \mathrm{~m}$ wide and carries a discharge of $2.0 \mathrm{~m}^{3} / \mathrm{s}$ with a depth of $0.4 \mathrm{~m}$. The channel transitions to a maximum width contraction at a downstream location, without influencing the upstream flow conditions. The width (in meters) at the maximum contraction is $\_\_\_\_\_\_\_$ (rounded off to $2$ decimal places).